This invention relates to novel isoindoline derivatives and to a process for producing these derivatives.
It is known that various heterocylic nuclei can be advantageously incorporated into dye structures to create or enhance photographic utility of the dye. Dyes containing isoindole nuclei are also known, such as the azadicarbocyanine dyes disclosed in I1' chenko and Radchenko in Khim. Getero. Soldinenii, 1971, at pp. 454-458. However, these isoindole dyes have not proven to be useful as spectral sensitizing dyes.
Leister, et al, U.S. Pat. No. 3,646,033 discloses isoindoline derivatives asymetrically substituted in the 1- and 3-position corresponding to the general formula ##STR3## in which the cyclic radical R is an aromatic ring, a substituted aromatic ring, a tetrahydrogenated aromatic ring, a nitrogen-containing heterocyclic ring, or a sulfur-containing heterocyclic ring, and R.sub.1 and R.sub.2, which are different, are bivalent radicals of a compound which contains two active hydrogen atoms attached to a carbon or nitrogen atom, and a two stage process for making the same. The isoindoline derivatives are excellent dyestuffs for dyeing and printing synthetic fiber materials.
Chapman, U.S. Pat. No. 4,030,932 discloses sensitizing dyes containing an isoindole nucleus represented by the formula ##STR4## wherein R is an alkyl or substituted alkyl group; Q.sub.1 is a methine chain having an odd number of carbon atoms terminated with a nitrogen atom contained in a basic heterocyclic nucleus of the type used in cyanine dyes; D.sub.1 is a halogen atom, an alkoxy group, or a methine chain having an even number of carbon atoms terminated with a nitrogen atom contained in a basic heterocyclic nucleus of the type used in cyanine dyes; and X.sup.- represents an anion.
It is an object of this invention to provide a isoindoline cationic dye which is suitable for dyeing a wide variety of natural and synthetic fabrics.
It is another object to provide an isoindoline cationic dye which is suitable for modifying the sensitivity of silver halide emulsions.